It is known from, for example DE 20 2004 017 133 U1, to laterally displace an external operating element in the form of a magnetically held knob on a hob for a first operating function, such as indicating the selection of a hotplate. The operating element can be subsequently returned to its starting position in order to then determine by rotation the power level for the selected hotplate. Such an operating element is basically also known from U.S. Pat. No. 5,920,131 A.
The problem of the invention is to provide such an operating device and an operating method with which extended operating functions are made possible through a novel structure and a novel operation.